Add clarity to microstate, macrostate and ensemble

[groponp]

The review is very good, but there are many gaps when it comes to defining the basic terms that are the basis of everything expressed in the different methods. These are the concept of microstate, macrostate, and ensemble, but in terms of a biological system (ammonia in water for example). Many texts make this confusing, because they expose all the cases around a set of N particles, and assume the energy (the Hamiltonian) for each particle, but in a simulation, the Hamiltonian (potential only), is the one evaluated (bonds , angles, etc), how do you describe a microstate, macrostate or ensemble around it? An idea for this could be to describe a protein in water, where all the possible configurations of the protein's atoms would be all of its microstates, and the grouping of these microstates to give an open and closed conformation would be the concept of the two. macrostates (metastates). Here, then, the trajectory of the system (snapshot) could be equivalent to the concept of assembly (the idealization of the multiplies replicas of the system), from there one can start to define microstates of a bond, angle, etc. Now when the Boltzmann distribution is defined, one has to be careful how to evaluate the microstate of a system and its partition function, because sometimes it seems that one the energy in the exponential of could be the energy of a particle and not the sum of the energy of the particles (that is, the sum of the Hamiltonian). I think these clarifications will be very interesting.

Geo.